SG137A/SG237A/SG337A
SG137/SG237/SG337
1.5 AMP NEGATIVE
ADJUSTABLE REGULATOR
DESCRIPTION
The SG137A family of negative adjustable regulators will deliver up to 1.5A
output current over an output voltage range of -1.2V to -37V. Silicon General
has made significant improvements in these regulators compared to previous
devices, such as better line and load regulation, and a maximum output voltage
error of 1%. The SG137 family uses the same chip design and guarantees
maximum output voltage error of
±2%.
Every effort has been made to make these devices easy to use and difficult to
damage. Internal current and power limiting coupled with true thermal limiting
prevents device damage due to overloads or shorts even if the regulator is not
fastened to a heat sink.
The SG137A/137 family of products are ideal complements to the SG117A/
117 adjustable positive regulators.
FEATURES
•
•
•
•
•
1 % output voltage tolerance
0.01%/V line regulation
0.5% load regulation
0.02%/W thermal regulation
Available in hermetic TO-220
HIGH RELIABILITY FEATURES
-SG137A/SG137
♦
Available to MIL-STD-883 and DESC SMD
♦
Scheduled for MIL-M38510 QPL listing
♦
MIL-M38510/11804BYA - JAN137K
♦
LMI level "S" processing available
BLOCK DIAGRAM
2/92 Rev 1.1 2/94
Copyright
©
1994
1
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG137A/SG137 SERIES
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Power Dissipation ..........................................
Internally Limited
Input to Output Voltage Differential ....................................
40V
Storage Temperature Range ............................
-65°C to 150°C
Note 1. Exceeding these ratings could cause damage to the device.
Operating Junction Temperature
Hermetic (K, R, T, L, IG-Packages) ........................... 150°C
Lead Temperature (Soldering, 10 Seconds) ............. 300°C
THERMAL DATA
K Package:
Thermal Resistance-
Junction to Leads
,
θ
JC
................ 3.0°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
............... 35°C/W
R Package:
Thermal Resistance-
Junction to Leads
,
θ
JC
................ 5.0°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
.............. 40°C/W
T Package:
Thermal Resistance-
Junction to Leads
,
θ
JC
................. 15°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
............ 120°C/W
IG Package:
Thermal Resistance-
Junction to Leads
,
θ
JC
................ 3.5°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
.............. 42°C/W
L Package:
Thermal Resistance-
Junction to Leads
,
θ
JC
................. 35°C/W
Thermal Resistance-
Junction to Ambient
,
θ
JA
............ 120°C/W
Note A. Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
Note B. The above numbers for
θ
JC
are maximums for the limiting
thermal resistance of the package in a standard mount-
ing configuration. The
θ
JA
numbers are meant to be
guidelines for the thermal performance of the device/pc-
board system. All of the above assume no ambient
airflow.
RECOMMENDED OPERATING CONDITIONS
(Note 2 & 3)
Input Voltage Range ..............................-(V
OUT
+ 3.5V) to -36V
Operating Junction
SG137A/SG137
SG237A/SG237
SG337A/SG337
Temperature Range
............................................
-55°C to 150°C
............................................
-25°C to 150°C
............................................. 0°C to 125°C
Note 2. Range over which the device is functional.
Note 3. These ratings are applicable for junction temperatures of less than 135°C.
ELECTRICAL CHARACTERISTICS
(Unless otherwise specified, these specifications apply over full operating ambient temperatures for SG137A/SG137 with -55°C
≤
T
A
≤
150°C, SG237A/
SG237 with -25°C
≤
T
A
≤
150°C, SG337A/SG337 with 0°C
≤
T
A
≤
125°C, |V
IN
- V
OUT
| = 5.0V, and for I
OUT
= 500mA (K, R, and IG power packages) and I
OUT
= 100mA (T and L packages). Although power dissipation is internally limited, these specifications are applicable for power dissipations of 2Ω for the T and
L packages, and 20Ω for the K, R, and IG packages. I
MAX
is 1.5A for the K, R, and IG packages and 0.5A for the T and L packages. Low duty cycle pulse
testing techniques are used which maintains junction and case temperatures equal to the ambient temperature.)
Parameter
Reference Voltage
(Note 6)
Line Regulation
(Note 4, 6)
Load Regulation
(Note 4)
Test Conditions
I
OUT
= 10mA, T
A
= 25°C
3V
≤
|V
IN
- V
OUT
|
≤
40V, 10mA
≤
I
OUT
≤
I
MAX
3V
≤
|V
IN
- V
OUT
|
≤
40V, I
OUT
≤
I
MAX
T
A
= 25°C
10mA
≤
I
OUT
≤
I
MAX
|V
OUT
|
≤
5V, T
A
= 25°C
|V
OUT
|
≥
5V, T
A
= 25°C
|V
OUT
|
≤
5V
|V
OUT
|
≥
5V
T
A
= 25°C, 10ms pulse
V
OUT
= -10V, f =120Hz
C
ADJ
= 0, T
A
= 25°C
C
ADJ
= 10µF
T
A
= 25°C
3V
≤
|V
IN
- V
OUT
|
≤
40V
10mA
≤
I
OUT
≤
I
MAX
SG137A/SG237A
SG137/SG237
Units
Min. Typ. Max. Min. Typ. Max.
-1.238 -1.250 -1.262 -1.225 -1.250 -1.275
V
-1.220 -1.250 -1.280 -1.200 -1.250 -1.300
V
0.005 0.01
5
25
0.1
0.5
10
50
0.2
1.0
0.002 0.02
60
70
66
80
65
1.0
0.2
0.01 0.02
15
25
0.3
0.5
20
50
0.3
1.0
0.002 0.02
60
77
65
2
0.5
%/V
mV
%
mV
%
%/W
dB
dB
µA
µA
µA
Thermal Regulation
(Note 5)
Ripple Rejection
66
100
5
2
Adjust Pin Current
Adjust Pin Current Change
(Note 6)
100
5
5
2/92 Rev 1.1 2/94
Copyright
©
1994
2
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG137A/SG137 SERIES
ELECTRICAL CHARACTERISTICS
Parameter
Minimum Load Current
Current Limit
(continued)
Test Conditions
|V
IN
- V
OUT
|
≤
40V
|V
IN
- V
OUT
|
≤
10V
|V
IN
- V
OUT
|
≤
15V
K, P, R, IG Packages
T, L, Packages
|V
IN
- V
OUT
|
≤
40V, T
J
= 25°C
K, P, R, IG Packages
T, L, Packages
T
A
= 125°C, 1000 Hours
T
A
= 25°C, 10Hz
≤
f
≤
10 KHz
(Note 5)
SG137/SG237
SG137A/SG237A
Min. Typ. Max. Min. Typ. Max.
2.5
5.0
2.5
5.0
1.2
3
1.2
3.0
1.5
0.5
2.2
0.8
3.2
1.5
1.0
0.5
1.5
1.0
1.5
0.5
2.2
0.8
Units
mA
mA
A
A
A
A
%
%
%
Temperature Stability
(Note 5)
Long Term Stability
(Note 5)
RMS Output Noise (% of V
OUT
)
0.24 0.4
0.15 0.25
0.6
0.3
0.003
0.24 0.4
0.15 0.25
0.6
0.3
0.003
1.0
Parameter
Reference Voltage
(Note 6)
Line Regulation
(Note 4, 6)
Load Regulation
(Note 4)
Test Conditions
I
OUT
= 10mA, T
A
= 25°C
3V
≤
|V
IN
- V
OUT
|
≤
40V, 10mA
≤
I
OUT
≤
I
MAX
3V
≤
|V
IN
- V
OUT
|
≤
40V, I
OUT
≤
I
MAX
T
A
= 25°C
10mA
≤
I
OUT
≤
I
MAX
|V
OUT
|
≤
5V, T
A
= 25°C
|V
OUT
|
≥
5V, T
A
= 25°C
|V
OUT
|
≤
5V
|V
OUT
|
≥
5V
T
A
= 25°C, 10ms pulse
V
OUT
= -10V, f =120Hz
C
ADJ
= 0, T
A
= 25°C
C
ADJ
= 10µF
T
A
= 25°C
3V
≤
|V
IN
- V
OUT
|
≤
40V
10mA
≤
I
OUT
≤
I
MAX
|V
IN
- V
OUT
|
≤
40V
|V
IN
- V
OUT
|
≤
10V
|V
IN
- V
OUT
|
≤
15V
K, P, R, IG-Packages
T, L-Packages
|V
IN
- V
OUT
|
≤
40V, T
J
= 25°C
K, P, R, IG- Packages
T, L-Packages
T
A
= 125°C, 1000hr
T
A
= 25°C, 10Hz
≤
f
≤
10KHz
(Note 5)
SG337
SG337A
Units
Min. Typ. Max. Min. Typ. Max.
V
-1.238 -1.250 -1.262 -1.213 -1.250 -1.287
V
-1.220 -1.250 -1.280 -1.200 -1.250 -1.300
0.005 0.01
5
25
0.1
0.5
50
10
0.2
1.0
0.002 0.02
60
70
66
80
65
1.0
0.2
2.5
1.2
2.2
0.8
0.01 0.04
15
50
0.3
1.0
20
70
0.3
1.5
0.003 0.04
60
77
65
2
0.5
2.5
1
2.2
0.8
0.4
0.17
0.6
0.3
0.003
%/V
mV
%
mV
%
%/W
dB
dB
µA
µA
µA
mA
mA
A
A
A
A
%
%
%
Thermal Regulation
(Note 5)
Ripple Rejection
66
100
5
2
5
3
3.5
1.5
1.0
0.5
1.5
1.0
1.5
0.5
0.15
0.10
Adjust Pin Current
Adjust Pin Current Change
(Note 6)
Minimum Load Current
Current Limit
100
5
5
10
6
1.5
0.5
Temperature Stability
(Note 5)
Long Term Stability
(Note 5)
RMS Output Noise (% of V
OUT
)
0.24 0.5
0.15 0.25
0.6
0.3
0.003
1.0
Note 4. Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating
effects are covered under the specification for thermal regulation.
Note 5. These parameters, although guaranteed, are not tested in production.
Note 6. I
MAX
for K, R, and IG packages is V
IN
- V
OUT
= 3V / 1.5A and V
IN
- V
OUT
= 40V / 240mA. For T and L packages I
MAX
is V
IN
- V
OUT
= 3V / 500mA
and V
IN
- V
OUT
= 40V / 150mA.
2/92 Rev 1.1 2/94
Copyright
©
1994
3
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG137A/SG137 SERIES
CHARACTERISTIC CURVES
FIGURE 1.
INPUT/OUTPUT DIFFERENTIAL
VS. OUTPUT CURRENT
FIGURE 2.
REFERENCE VOLTAGE VS. TEMPERATURE
FIGURE 3.
CURRENT VS. INPUT/OUTPUT DIFFERENTIAL
FIGURE 4. *
OUTPUT VOLTAGE DEVIATION
VS. OUTPUT CURRENT
* The SG137A has load regulation compensation which
makes the typical unit read close to zero. This band
represents the typical production spread.
FIGURE 5.
INPUT/OUTPUT DIFFERENTIAL
VS. OUTPUT CURRENT
FIGURE 6.
ADJUSTMENT CURRENT VS. TEMPERATURE
APPLICATION INFORMATION
OUTPUT VOLTAGE
The output voltage is determined by two external resistors, R
1
&
R
2
(see Figure 7).
Where: V
REF
=Reference Voltage, I
ADJ
= Adjustment Pin Current.
In most applications, the second term is small enough to be
ignored, typically about 0.5% of V
OUT
. In more critical applica-
tions, the exact formula should be used, with I
ADJ
equal to 65µA.
Solving for R
2
yields:
R
2
=
V
OUT
- V
REF
V
REF
+ I
ADJ
R
1
FIGURE 6
The exact formula for the output voltage is:
V
OUT
= V
REF
(
R
2
+ R
1
R
1
)
+I
ADJ
(R
2
)
Smaller values of R
1
and R
2
will reduce the influence of I
ADJ
on the
output voltage, but the no-load current drain on the regulator will
be increased. Typical values for R
1
are between 100Ω and 300Ω,
giving 12.5 mA and 4.2mA no-load current respectively. There
is an additional consideration in selecting R
1
the minimum load
current specification of the regulator. The operating current of
2/92 Rev 1.1 2/94
Copyright
©
1994
4
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
SG137A/SG137 SERIES
APPLICATION INFORMATION
(continued)
EXAMPLES:
1. A precision 10V regulator to supply up to 1Amp load current.
a. Select R
1
= 100Ω to minimize effect of I
ADJ
b. Calculate R
2
=
V
OUT
- V
REF
10V - 1.25V
=
= 704W
(V
REF
/R
1
) + I
ADJ
(1.25V/100W) + 65mA
the SG137A flows from input to output. If this current is not
absorbed by the load, the output of the regulator will rise above
the regulated value. The current drawn by R
1
and R
2
is normally
high enough to absorb the current, but care must be taken in no–
load situations where R
1
and R
2
have high values. The maximum
value for the operating current, which must be absorbed, is 5mA
for the SG137A, If input-output voltage differential is less than
10V, the operating current that must be absorbed drops to 3mA.
The output stability, load regulation, line regulation, thermal
2. A 15V regulator to run off batteries and supply 50mA.
V
IN
MAX = 25V
a. To minimize battery drain, select R
1
as high as possible
R
1
=
1.25V
3mA = 417Ω, use 404Ω, 1%
TYPICAL APPLICATIONS
regulation, temperature drift, long term drift, and noise, can be
improved by a factor of 6.6 over the standard regulator configu-
ration. This assumes a zener whose drift and noise is considera-
bly better than the regulator itself. The LM329B has 20PPM/°C
maximum drift and about 10 times lower noise than the regulator.
In the application shown Figure 8, regulators #2 to #N will track
regulator #1 to within ±24mV initially, and to ±60mV over all load,
line, and temperature conditions. If any regulator output is
shorted to ground, all other outputs will drop to -2V. Load
regulation of regulators #2 to #N will be improved by V
OUT
/1.25V
compared to a standard regulator, so regulator #1 should be the
one which has the lowest load current.
FIGURE 8 - MULTIPLE TRACKING REGULATORS
FIGURE 9 - HIGH STABILITY REGULATOR
FIGURE 10 - CURRENT REGULATOR
FIGURE 11 - DUAL TRACKING SUPPLY ±1.25V to ±20V
2/92 Rev 1.1 2/94
Copyright
©
1994
5
11861 Western Avenue
∞
Garden Grove, CA 92841
(714) 898-8121
∞
FAX: (714) 893-2570
L
INFINITY
Microelectronics Inc.
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